/Engine/Source/Runtime/Renderer/Public/VariableRateShadingImageManager.h
Explicit VRS source flags; each type of VRS image generated here will have it's own flag defined in this bitfield. These flags can be used for any particular rendering path to exclude specific types of VRS generation; e.g. Used to allow exclusion of certain types when getting image.
enum EVRSSourceType { FixedFoveation = 0x1, EyeTrackedFoveation = 0x2, ContrastAdaptiveShading = 0x4, All = FixedFoveation | EyeTrackedFoveation | ContrastAdaptiveShading, XRFoveation = FixedFoveation | EyeTrackedFoveation, None = 0x0, }